Photodissociation dynamics of Ar3

Abstract Mass selected Ar 3 + clusters are photodissociated by a polarized argon-ion laser beam at 514, 488 and 458 nm. Only Ar + /2Ar products are observed. Laser polarization dependence of the product laboratory kinetic energy peak shapes indicates that a “pure” parallel transition is responsible for the photodissociation. Analysis indicates it is almost certainly a 2 Σ u + ← 2 Σ g + transition resulting in Ar + ( 2 P 1 2 ). The product kinetic energy distribution is strongly bimodal with approximately 75% of the products at high kinetic energy (near the energy conservation limit) and 25% with near zero kinetic energy. A model is developed that explains this unexpected (and dynamically informative) result.